#include <stdio.h>
#include <stdlib.h>
#include <math.h>

void addition() {
  printf("hello this is addition\n");
  const int num1;
  const int num2;
  printf("enter a number: ");
  scanf("%d", &num1);
  printf("enter another number: ");
  scanf("%d", &num2);
  printf("%d + %d = %d", num1, num2, num1 + num2);
}

void subtract() {
  printf("hello this is subtraction\n");
  const int num1;
  const int num2;
  printf("enter a number: ");
  scanf("%d", &num1);
  printf("enter another number: ");
  scanf("%d", &num2);
  printf("%d - %d = %d", num1, num2, num1 - num2);
}

void divide() {
  printf("hello this is division\n");
  const int num1;
  const int num2;
  printf("enter number: ");
  scanf("%d", &num1);
  printf("enter another number: ");
  scanf("%d", &num2);
  printf("%d / %d = %d", num1, num2, num1 / num2);
}

void multiply() {
  printf("hello this is multiplication");
  const int num1;
  const int num2;
  printf("enter a number: ");
  scanf("%d", &num1);
  printf("enter another number: ");
  scanf("%d", &num2);
  printf("%d * %d = %d", num1, num2, num1 * num2);
}

/* main */
int main ()
{
  int operatornum;
  printf("pick an operator: \n1. +\n2. -\n3. /\n4. *\n\n");
  scanf("%d", &operatornum);

  switch(operatornum)
  {
  case 1:
  addition();
  break;

  case 2:
  subtract();
  break;

  case 3:
  divide();
  break;

  case 4:
  multiply();
  break;

  default:
  break;
  }
}
